Frame for a cab of a mobile machine

ABSTRACT

A frame for a cab of a mobile machine includes first and second primary tubes, formed by hydroforming, connected to first and second secondary tubes. The first primary tube includes first and second about vertically extending portions and an about horizontally extending portion. The about vertically extending portions are configured to be connected to the mobile machine, and the about horizontally extending portion is disposed between the about vertically extending portions. The second primary tube includes first and second about vertically extending portions and an about horizontally extending portion. The about vertically extending portions of the second primary tube are configured to be connected to the mobile machine, and the about horizontally extending portion of the second primary tube is disposed between the about vertically extending portions of the second primary tube.

TECHNICAL FIELD

The disclosure is related to a frame for a cab of a mobile machine, andmore particularly to the cab frame that includes an integrated rolloverprotective structure (ROPS).

BACKGROUND

A mobile machine, such as an earthmoving machine, an excavation-typemachine, a mining machine, or the like, may be employed for anearthmoving, excavation, mining, or other operation. The mobile machinemay employ large earthmoving, excavating, drilling, or mining equipment,which is configured to dig and/or load earthen material from a worksite,to one or more large off-road haulage units, such as off-highway trucksthat may be driven by a driver or autonomously or semi-autonomouslycontrolled.

In many cases, the mobile machine is driven and/or otherwise operated bya person who sits in a cabin or cab that is connected to the machine.Often, the frame of the cab includes an integrated rollover protectivestructure (ROPS). As its name describes, the purpose of the ROPS is toprovide a structure that may prevent the cab frame and the cab frombeing crushed in a rollover.

Often times, the cab frame is constructed from numerous hollow metaltubes. Each individual tube is generally straight and has a constantcross section. Tubes of different lengths, having different interiorand/or different exterior dimensions, are used. In many cases, the cabframe is made up of dozens of these separate, differently-sized tubes.The tubes are welded together in different orientations relative to oneanother, to produce the desired shape of the cab frame, as well as toprovide the cab frame with portions meeting different dimensional andstrength requirements. It is a time-consuming, labor-intensive, andexpensive process to weld all of the tubes to produce the cab frame.Further, in order for the cab frame to be strong enough so that it mayprovide protection to the person in the cab during a rollover, gussetsare used to strengthen the weld joints that are formed between (i)generally vertically-extending tubes that are used to define the front,back, and sides of the cab, and (ii) generally horizontally-extendingtubes that are used to define the roof and floor of the cab. Welding thegussets to the metal tubes is also time-consuming, labor-intensive, andexpensive. Still further, the gussets block access to the corners of thecab frame, where it would otherwise be convenient to run electricalharnesses and ducting.

SUMMARY

In accordance with the disclosure, there is provided a frame for a cabof a mobile machine. The cab frame includes first and second primarytubes, formed by hydroforming, which are connected to first and secondsecondary tubes. The first primary tube includes first and second aboutvertically extending portions and an about horizontally extendingportion. The about vertically extending portions are configured to beconnected to the mobile machine, and the about horizontally extendingportion is disposed between the about vertically extending portions. Thesecond primary tube includes first and second about vertically extendingportions and an about horizontally extending portion. The aboutvertically extending portions of the second primary tube are configuredto be connected to the mobile machine, and the about horizontallyextending portion of the second primary tube is disposed between theabout vertically extending portions of the second primary tube.

Also in accordance with the disclosure, there is provided a frame for acab of a mobile machine that includes a first primary tube having firstand second about vertically extending portions and an about horizontallyextending portion disposed therebetween. The first primary tube hasdifferent strengths along a length thereof and forms a left side of thecab frame. The first primary tube is formed by hydroforming. The cabframe further includes a second primary tube having first and secondabout vertically extending portions and an about horizontally extendingportion disposed therebetween. The second primary tube has differentstrengths along a length thereof and forms a right side of the cabframe. The second primary tube is also formed by hydroforming. First andsecond secondary tubes are connected to the primary tubes.

Still further in accordance with the disclosure, there is provided amethod of manufacturing a frame for a cab of a mobile machine. Themethod includes forming a first primary tube by a hydroformingoperation, the first primary tube configured to form a left side of thecab frame. A second primary tube is formed by a hydroforming operation,the second primary tube configured to form a right side of the cabframe. First and secondary tubes are connected to both of the first andsecond primary tubes.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of a frame of a cab for a mobile machine, inaccordance with the disclosure.

FIG. 2A is a front view of a primary tube of the cab frame of FIG. 1.

FIG. 2B is a side view of the primary tube of FIG. 2A.

FIG. 2C is a back view of the primary tube of FIG. 2A.

FIG. 2D is a bottom view of the primary tube of FIG. 2A.

FIG. 3A is a front view of a secondary tube of the cab frame of FIG. 1.

FIG. 3B is a top view of the secondary tube of FIG. 3A.

FIG. 3C is a side view of the secondary tube of FIG. 3A.

FIG. 4A is a front view of an alternate secondary tube that may be usedin the cab frame of the mobile machine, in accordance with thedisclosure.

FIG. 4B is a top view of the secondary tube of FIG. 4A.

FIG. 4C is a side view of the secondary tube of FIG. 4A.

FIG. 5 is a detail view of the cab frame of FIG. 1, showing connectionsbetween the primary and secondary tubes.

FIG. 6 is a detail view of the cab frame of FIG. 1, similar to FIG. 5but looking straight toward a front of one of the secondary tubes.

DETAILED DESCRIPTION

FIG. 1 is an isometric view of a frame of a cabin or cab for a mobilemachine, in accordance with the disclosure. It is contemplated that cabframe 100 may be connected to any type of mobile machine, such as butnot limited to an earthmoving machine, an excavation-type machine, amining machine, or the like, which may (but need not) be employed for anearthmoving, excavation, mining, or other operation. Such a mobilemachine may (but need not) employ large earthmoving, excavating,drilling, or mining equipment, which is configured to dig and/or loadearthen material from a worksite, to one or more large off-road haulageunits, such as off-highway trucks that may be driven by a driver orautonomously or semi-autonomously controlled. It is further contemplatedthat the cab frame may (but need not) have connected thereto one or moreof a front wall, a back wall, a left-side wall, a right-side wall, aroof, a windshield, a rear window, one or more side windows, one or moredoors, or any other cab-defining structure, to thereby define either anopen cab, an at-least-partially-closed cab, or a fully-closed cab, inwhich a person may sit to drive and/or otherwise operate the mobilemachine. It is still further contemplated that cab frame 100 may includean integrated rollover protective structure (ROPS), which may preventthe cab frame and/or any cab-structure connected to the cab frame frombeing crushed in a rollover.

As shown in FIG. 1, cab frame 100 may include two (2) primary tubes 200and two (2) secondary tubes 300, which may be connected to one anotherto form a complete frame on which the cab for the mobile machine may bebuilt. It is contemplated that primary tubes 200 and secondary tubes 300may be welded to one another. It is to be understood, however, thatprimary tubes 200 and secondary tubes 300 may be connected to oneanother by any other procedure, such as by bolting. FIGS. 2A-2D arefront, side, back, and bottom views, respectively, of one of the primarytubes 200.

One of the primary tubes 200 used in cab frame 100 is now discussed. Theother primary tube 200 used in cab frame 100 may, but need not, besubstantially identical. As shown in the figures, primary tube 200 maybe a hollow tube. Contours of primary tube 200 may be formed by ahydroforming operation. Specifically, during the hydroforming operation,a hollow structure, such as a straight tube that has a constant circularcross section, may be held in a mold, and a pressurized fluid (i.e.,liquid or gas) may be flowed through the interior of the hollowstructure. The mold may have the contours of primary tube 200 shown inFIGS. 2A-2D. As a result, the hollow structure may be plasticallydeformed and may take on the shape of the mold. Through this operation,primary tube 200 may be formed in a single manufacturing step. The moldmay also form one or more openings along the length of primary tube 200,to permit the fluid to flow out of the hollow interior of primary tube200 after the hydroforming operation.

Primary tube 200 includes two (2) about vertically extending portions210 that are connected through two (2) curved portions 220 to abouthorizontally extending portion 230. Each of portions 210 and 230 may beabout straight, and may be disposed about perpendicular to one another.For each portion 210, width W210 may be about constant along an aboutentire length of portion 210, while for portion 230, width W230 may vary(i) from a maximum at the ends that connect to portions 210 throughcurved portions 220 (ii) to a minimum at an about center of portion 230.Further, the value of the width W210 of each of portions 210 may begreater than a minimum value of the width W230 of portion 230. As shownin the drawings, the width W210 may be measured in a direction thatextends from an inside to an outside edge of portion 210. As also shownin the drawings, the width W230 may be measured in a direction thatextends from a top to a bottom edge of portion 230.

For each portion 210, depth D210 may be about constant along an aboutentire length of portion 210, while for portion 230, depth D230 may vary(i) from a minimum at the ends that connect to portions 210 throughcurved portions 220 (ii) to a maximum at an about center of portion 230.Further, the value of the depth D210 of each of portions 210 may be lessthan a maximum value of the depth D230 of portion 230. As shown in thedrawings, the depth D210 may be measured in a direction that extendsfrom a front to a back side of portion 210. As also shown in thedrawings, the depth D230 may be measured in a direction that extendsfrom a front to a back side of portion 230. The widths and/or the depthsof each of the two (2) curved portions 220 may be chosen to transitionfrom the widths and/or depths of portion 210 to the widths and/or depthsof portion 230, respectively.

Each of portions 210 may define surface 215 and surface 217. Eachsurface 215 may be an about flat surface, and may lie in a flat plane.Each surface 217 may be an about flat surface, and may be disposed at anangle relative to surface 215, and the angle may be variable or may beabout constant along the about entire length of portion 210. Bydisposing surface 215 at an angle relative to surface 217, primary tube200 may resist bending in multiple directions or along multiple axes.Further, surfaces 215 for each of the two (2) portions 210 may liewithin the same flat plane.

Similarly, portion 220 may define surface 225 and surface 227, wheresurface 225 may be an about flat surface and may lie in a flat plane,and surface 227 may be an about flat surface and may be disposed at anangle relative to surface 225, where the angle may be variable or may beabout constant along the about entire length of portion 220. Further,surface 225 may lie within the same flat plane in which surfaces 215 ofeach of the two (2) portions 210 lie. In other words, surfaces 215 and225 may define and lie within the same flat plane. Additionally oralternately, portion 230 may define surface 235 and surface 237, wheresurface 235 may be an about flat surface and may lie in a flat plane,and surface 237 may be an about flat surface and may be disposed at anangle relative to surface 235, where the angle may be variable or may beabout constant along the about entire length of portion 230. Further,surface 235 may lie within the same flat plane in which surfaces 215 ofeach of the two (2) portions 210 lie. In other words, surfaces 215, 225,and 235 may define and lie within the same flat plane. By disposingsurfaces 225 and 235 at one or more angles relative to surfaces 227 and237, respectively, primary tube 200 may resist bending in multipledirections or along multiple axes. Each of the angles between (i)surfaces 215 and 217, (ii) surfaces 225 and 227, and (iii) surfaces 235and 237 may be the same angle, or may be different angles.

As shown in the figures and as discussed above, cab frame 100 mayinclude two (2) primary tubes 200. It is contemplated that primary tubes200 may be disposed on the mobile machine such that: one of the primarytubes 200 defines a left side of cab frame 100 and of any cab-structureconnected thereto, such as a left-side wall of the cab; the other one ofthe primary tubes 200 defines a right side of cab frame 100 and of anycab-structure connected thereto, such as a right-side wall of the cab;and any front or back walls of the cab are connected between the two (2)primary tubes 200. By this arrangement, for example, a door on the leftside of the cab may connect to one of the primary tubes 200 (referred tohere as left-side tube 200), and may close against each of (i) surfaces215 of each of the two (2) portions 210 of left-side tube 200, (ii)surface 225 of curved portion 220 of left-side tube 200, and (iii)surface 235 of portion 230 of left-side tube 200. Similarly, a door onthe right side of the cab may connect to the other one of the primarytubes 200 (referred to here as right-side tube 200), and may closeagainst each of (i) surfaces 215 of each of the two (2) portions 210 ofright-side tube 200, (ii) surface 225 of curved portion 220 ofright-side tube 200, and (iii) surface 235 of portion 230 of right-sidetube 200. It is to be understood that a door or doors may be connectedto either or both of left-side or right-side tube 200, or that a doormay be entirely omitted from any cab built on cab frame 100.

When a door is to be used on either or both of left-side tube 200 orright-side tube 200, the corresponding primary tube 200 may include oneor more sets of holes 219 configured to receive screws, bolts, or otherfasteners that connect one or more door hinges to cab frame 100. Holes219 may be formed in surface 217 of at least one of the two (2) portions210. Holes 219 may be formed during the hydroforming operation thatproduces primary tube 200, or may be formed after production of primarytube 200. Further, when holes 219 are formed during the hydroformingoperation that produces primary tube 200, holes 219 may be formed insurface 217 of each of the two (2) portions 210 of primary tube 200. Bythis arrangement, a door may be mounted to either portion 210 (i.e., oneither side) of primary tube 200. Alternately or additionally, althoughnot shown in the drawings, one or more sets of holes may be formed insurface 215 of either or both of the two (2) portions 210.

The shape and/or contours of the extreme ends of primary tube 200 may beconfigured for connection of cab frame 100 to the mobile machine.Specifically, each of the two (2) primary tubes 200 may have endssuitable to be welded to the mobile machine. It is to be understood,however, that either or both of primary tubes 200 may be connected tothe mobile machine by another procedure, such as by bolting.

As shown in FIG. 1, cab frame 100 may also include two (2) secondarytubes 300 that are connected to the two (2) primary tubes 200. FIGS.3A-3C are front, top, and side views, respectively, of one of thesecondary tubes 300.

One of the secondary tubes 300 used in cab frame 100 is now discussed.The other secondary tube 300 used in cab frame 100 may, but need not, besubstantially identical. As shown in the figures, secondary tube 300 maybe a hollow tube. Contours of secondary tube 300 may be formed by ahydroforming operation. Specifically, during the hydroforming operation,a hollow structure, such as a straight tube that has a constant circularcross section, may be held in a mold, and a pressurized fluid (i.e.,liquid or gas) may be flowed through the interior of the hollowstructure. The mold may have the contours of secondary tube 300 shown inFIGS. 3A-3C. As a result, the hollow structure may be plasticallydeformed and may take on the shape of the mold. Through this operation,secondary tube 300 may be formed in a single manufacturing step. Themold may also form one or more openings along the length of secondarytube 300, to permit the fluid to flow out of the hollow interior ofsecondary tube 300 after the hydroforming operation. It is to beunderstood, however, that secondary tube 300 may be formed by anothermanufacturing operation different from the hydroforming operation. Forexample, as discussed in further detail below, FIGS. 4A-4C show aspecific, alternate secondary tube 400 that may be formed by anotheroperation.

Returning to FIGS. 3A-3C, secondary tube 300 may include abouthorizontally extending portion 330 disposed between two (2) curvedportions 320 that are configured to be connected to primary tubes 200 toform cab frame 100. Portion 330 may be about straight. Width W330 ofportion 330 may vary (i) from a maximum at the ends that connect toprimary tubes 200 through curved portions 320 (ii) to a minimum at anabout center of portion 330. Depth D330 of portion 330 may vary (i) froma minimum at the ends that connect to primary tubes 200 through curvedportions 320 (ii) to a maximum at an about center of portion 330.Further, specific contours of the extreme ends of curved portions 320may be prepared to facilitate connection of secondary tube 300 to two(2) primary tubes 200 when forming cab frame 100. As shown in thedrawings, the width W330 may be measured in a direction that extendsfrom a top to a bottom edge of portion 330. As also shown in thedrawings, the depth D330 may be measured in a direction that extendsfrom a front to a back face of portion 330.

As shown in the figures and as discussed above, cab frame 100 mayinclude two (2) secondary tubes 300. It is contemplated that secondarytubes 300 may be connected to primary tubes 200 such that topmostsurfaces of primary and secondary tubes 200 and 300 define a flat planeand define a top of cab frame 100. A roof of the cab may be connected tothese topmost surfaces, so as to lie in the flat plane. Further, thecontours of curved portions 320 of secondary tubes 300, as well as thecontours of curved portions 220 of primary tubes 200, result in gapsbetween (i) the plane formed by the topmost surfaces of primary andsecondary tubes 200 and 300, and (ii) curved portions 220 and 320 ofprimary and secondary tubes 200 and 300. FIGS. 5 and 6 show examples ofthese gaps, indicated as gaps G. As shown in the figures, gaps G areformed at corners where secondary tubes 300 are connected to primarytubes 200.

Although FIG. 1 shows cab frame 100 that includes (2) secondary tubes300 that are illustrated in FIGS. 3A-3C, it is contemplated that othertypes of secondary tubes may be used in cab frame 100. FIGS. 4A-4C showan example of a specific, alternate secondary tube 400 that may be usedin cab frame 100 in place of each of the two (2) secondary tubes 300. Itis to be understood, however, that in accordance with the disclosure cabframe 100 may alternately use one (1) secondary tube 300 and one (1)secondary tube 400, or another type of secondary tube with either one(1) secondary tube 300 or one (1) secondary tube 400. It is contemplatedthat primary tubes 200 and any secondary tubes 400 used in cab frame 100may be welded to one another. It is to be understood, however, thatprimary tubes 200 and any secondary tubes 400 used in cab frame 100 maybe connected to one another by any other procedure, such as by bolting.

Secondary tube 400 may be formed during one or more blanking operations,stamping operations, material deformation operations, and/or materialremoval operations. As shown in these figures, secondary tube 400 mayinclude about horizontally extending portion 430 disposed between two(2) curved portions 420 that are configured to be connected to primarytubes 200. Portion 430 may be about straight. Width W430 of portion 430may vary (i) from a maximum at the ends that connect to primary tubes200 through curved portions 420 (ii) to a minimum at an about center ofportion 430. Depth D430 of portion 430 may vary (i) from a maximum atthe ends that connect to primary tubes 200 through curved portions 420(ii) to a minimum at an about center of portion 430. Further, specificcontours of the extreme ends of curved portions 420 may be prepared tofacilitate connection to the two (2) primary tubes 200 to form cab frame100. As shown in the drawings, the width W430 may be measured in adirection that extends from a top to a bottom edge of portion 430. Asalso shown in the drawings, the depth D430 may be measured in adirection that extends from a front to a back face of portion 430.

As discussed above, cab frame 100 may include two (2) secondary tubes400. It is contemplated that secondary tubes 400 may be connected toprimary tubes 200 such that topmost surfaces of primary and secondarytubes 200 and 400 define a flat plane and define the top of cab frame100. The roof of the cab may be connected to these topmost surfaces, soas to lie in the flat plane. Further, the contours of curved portions420 of secondary tubes 400, as well as the contours of curved portions220 of primary tubes 200, result in a gap between (i) the plane formedby the topmost surfaces of primary and secondary tubes 200 and 400, and(ii) curved portions 220 and 420 of primary and secondary tubes 200 and400. These gaps are similar to gaps G formed by primary and secondarytubes 200 and 300, examples of which are shown in FIGS. 5 and 6.

INDUSTRIAL APPLICABILITY

The foregoing disclosure is directed to a cab frame for a mobilemachine. It is contemplated that cab frame 100 may be connected to anytype of mobile machine, such as but not limited to an earthmovingmachine, an excavation-type machine, a mining machine, or the like,which may be employed for an earthmoving, excavation, mining, or otheroperation. Such a mobile machine may employ large earthmoving,excavating, drilling, or mining equipment. It is contemplated that cabframe 100 may include an integrated rollover protective structure(ROPS), which may prevent the cab frame and/or any cab-structureconnected to the cab frame from being crushed in a rollover.

In accordance with the disclosure, cab frame 100 for a mobile machinemay include two (2) primary tubes 200 and two (2) secondary tubes 300.Primary tubes 200 may be substantially identical to one another.Additionally or alternately, secondary tubes 300 may be substantiallyidentical to one another. Thus, the entirety of cab frame 100, which mayinclude an integrated rollover protective structure (ROPS), may beformed by using only these two (2) parts (i.e., only primary andsecondary tubes 200 and 300), two (2) times each. This is in contrast tothe dozens of tubes that are used in the known cab frame that includesan integrated ROPS. Thus, cab frame 100 may be much less complex thanthe known cab frame, may be much less labor-intensive to produce, andmay be manufactured less expensively and/or in a shorter period of time.

As discussed above, primary tube 200 may be formed by a hydroformingoperation. Thus, primary tube 200 may be provided with one or moredesired, specific characteristics and yet be produced by a singlemanufacturing operation. These characteristics may include desired,specific contours for primary tube 200, which may facilitate or enableconnection of primary tube 200 to the mobile machine, connection ofprimary tube 200 to secondary tubes (such as secondary tubes 300 or400), or connection of primary tube 200 to other cab-structurecomponents.

These characteristics may additionally or alternately include a desired,specific interior and/or exterior cross-section or another dimension forany particular portion of primary tube 200, which may differ from across-section or corresponding dimension of another portion of primarytube 200. The interior and exterior cross-sections and dimensions of aportion of the tube may be related to the strength of that particularportion of the tube. Thus, for example, the width W210 and the depthD210 of portion 210 of primary tube 200 may be chosen to provide adesired, specific strength for portion 210. Further, the width W230 andthe depth D230 of portion 230 of primary tube 200 may be different fromthe width W210 and the depth D210 of portion 210, respectively, and maybe chosen to provide a desired, specific strength for portion 230. Thestrength of portion 230 may be different than or the same as thestrength of portion 210. Therefore, primary tube 200 may be providedwith a desired, specific strength profile for different portions (e.g.,portion 210, 220, or 230) of primary tube 200.

Similarly, the dimensions, such as the depths and the widths, may bevaried along a length of a particular portion of primary tube 200. As aresult, a desired, minimum strength along the length of that particularportion of primary tube 200 may be maintained even though the dimensionsvary along the length of that same portion. Additionally or alternately,a desired, specific strength profile along the length of that particularportion of primary tube 200 may be provided even though the dimensionsvary along the length of that same portion. In any case, the dimensionsalong the length of that particular portion of primary tube 200 may beoptimized. Thus, as shown in the figures, such as FIGS. 1, 2A-2C, and 5,the width W230 may be minimized at the center of portion 230 and thedepth D230 may be maximized at the center of portion 230, while thedesired, minimum strength of portion 230 may be maintained and/or thedesired, specific strength profile of portion 230 may be provided. Thisdimensional optimization may result in a maximization of headroomprovided near a center of cab frame 100, and subsequently near thecenter of the cab connected to cab frame 100, while portion 230 ofprimary tube 200 may still have adequate strength to resist crushing inthe event of a rollover.

As discussed above, secondary tube 300 may be formed by a hydroformingoperation. Thus, secondary tube 300 may be provided with one or moredesired, specific characteristics and yet be produced by a singlemanufacturing operation. These characteristics may include desired,specific contours for secondary tube 300, which may facilitate or enableconnection of secondary tube 300 to primary tubes 200, or connection ofsecondary tube 300 to any other cab-structure components.

These characteristics may additionally or alternately include a desired,specific interior and/or exterior cross-section or another dimension forany particular portion of secondary tube 300, which may differ from across-section or corresponding dimension of another portion of secondarytube 300. The interior and exterior cross-sections and dimensions of aportion of the tube may be related to the strength of that particularportion of the tube. Thus, secondary tube 300 may be provided with adesired, specific strength profile for different portions (e.g., portion320 or 330) of secondary tube 300.

Similarly, the dimensions, such as the depths and the widths, may bevaried along a length of a particular portion of secondary tube 300. Asa result, a desired, minimum strength along the length of thatparticular portion of secondary tube 300 may be maintained even thoughthe dimensions vary along the length of that same portion. Additionallyor alternately, a desired, specific strength profile along the length ofthat particular portion of secondary tube 300 may be provided eventhough the dimensions vary along the length of that same portion. In anycase, the dimensions along the length of that particular portion ofsecondary tube 300 may be optimized. Thus, as shown in the figures, suchas FIGS. 1, 3A-3C, 5, and 6, the width W330 of portion 330 may beminimized at the center of portion 330 and the depth D330 of portion 330may be maximized at the center of portion 330, while the desired,minimum strength of portion 330 may be maintained and/or the desired,specific strength profile of portion 330 may be provided. Thisdimensional optimization may result in a maximization of headroomprovided near a center of cab frame 100, and subsequently near thecenter of the cab connected to cab frame 100, while portion 330 ofsecondary tube 300 may still have adequate strength to resist crushingin the event of a rollover.

The above-discussed arrangement may result in cab frame 100 with anintegrated ROPS which provides different portions having one or more of(i) desired and varying interior and/or exterior cross-section or otherdimensions, (ii) desired and varying minimum strength(s), and/or (iii)desired and varying strength profile(s), with only two (2) parts (e.g.,only primary and secondary tubes 200 and 300), each used two (2) timeseach, with each of the parts being formed in a single manufacturingoperation. This is in contrast to the dozens of differently-sized tubesthat are used in the known cab frame including an integrated ROPS. Thus,cab frame 100 may be much less complex than the known cab frame, may bemuch less labor-intensive to produce, and may be manufactured lessexpensively and/or in a shorter period of time.

As discussed above and as shown in the figures, including FIGS. 1, 5,and 6, secondary tubes 300 may be connected to primary tubes 200 suchthat topmost surfaces of primary and secondary tubes 200 and 300 definea flat plane and define the top of cab frame 100. The roof of the cabmay be connected to these topmost surfaces, so as to lie in the flatplane. Further, the contours of curved portions 320 of secondary tubes300, as well as the contours of curved portions 220 of primary tubes200, result in gaps between (i) the plane formed by the topmost surfacesof primary and secondary tubes 200 and 300, and (ii) curved portions 220and 320 of primary and secondary tubes 200 and 300. These gaps G mayprovide openings through which electrical harnesses or ducting may berun, in contrast to the known cab frame that includesstructurally-necessary gussets to reinforce, and thus which block accessto, these areas. It is to be understood that characteristics of primaryand secondary tubes 200 and 300, including but not limited tocharacteristics of curved portions 220 and 320, may be determined suchthat gaps G are of sufficient size to permit the harnesses and/or theducts to be disposed therethrough.

In accordance with the disclosure, cab frame 100 for a mobile machinemay include two (2) secondary tubes 400 in place of secondary tubes 300.Secondary tubes 400 may be substantially identical to one another. Useof two (2) secondary tubes 400 may be similar to the use of two (2)secondary tubes 300. For example, secondary tube 400 may be providedwith one or more desired, specific characteristics. Thesecharacteristics may include desired, specific contours for secondarytube 400, which may facilitate or enable connection of secondary tube400 to primary tubes 200, or connection of secondary tube 400 to anyother cab-structure components. These characteristics may additionallyor alternately include a desired, specific interior and/or exteriorcross-section or another dimension for any particular portion ofsecondary tube 400, which may differ from a cross-section orcorresponding dimension of another portion of secondary tube 400. Theinterior and exterior cross-sections and dimensions of a portion of thetube may be related to the strength of that particular portion of thetube. Thus, secondary tube 400 may be provided with a desired, specificstrength profile for different portions of secondary tube 400.

Similarly, the dimensions, such as the depths and the widths, may bevaried along a length of a particular portion of secondary tube 400. Asa result, a desired, minimum strength along the length of thatparticular portion of secondary tube 400 may be maintained even thoughthe dimensions vary along the length of that same portion. Additionallyor alternately, a desired, specific strength profile along the length ofthat particular portion of secondary tube 400 may be provided eventhough the dimensions vary along the length of that same portion. In anycase, the dimensions along the length of that particular portion ofsecondary tube 400 may be optimized. Thus, as shown in the figures, suchas FIGS. 4A-4C, the width W430 of portion 430 may be minimized at thecenter of portion 430 and the depth D430 of portion 430 may be minimizedat the center of portion 430, while the desired, minimum strength ofportion 430 may be maintained and/or the desired, specific strengthprofile of portion 430 may be provided. This dimensional optimizationmay result in a maximization of headroom provided near a center of cabframe 100, and subsequently near the center of the cab connected to cabframe 100, while portion 430 of secondary tube 400 may still haveadequate strength to resist crushing in the event of a rollover.

Similar to secondary tubes 300, secondary tubes 400 may be connected toprimary tubes 200 such that topmost surfaces of primary and secondarytubes 200 and 400 define a flat plane and define the top of cab frame100. The roof of the cab may be connected to these topmost surfaces, soas to lie in the flat plane. Further, the contours of curved portions420 of secondary tubes 400, as well as the contours of curved portions220 of primary tubes 200, result in gaps between (i) the plane formed bythe topmost surfaces of primary and secondary tubes 200 and 400, and(ii) curved portions 220 and 420 of primary and secondary tubes 200 and400. These gaps may provide openings through which electrical harnessesor ducting may be run. It is to be understood that characteristics ofprimary and secondary tubes 200 and 400 may be determined to providegaps of a desired, sufficient size to permit the harnesses and/or theducting to be disposed therethrough.

In further accordance with the disclosure, for one or both of theprimary tubes 200, each surface 215 of the two (2) portions 210, as wellas surface 225 of portion 220 and surface 235 of portion 230, may be anabout flat surface, and may lie in the same flat plane. Thus, primarytube 200 may provide a single flat surface to be used as a door sealingsurface, which is formed during the same manufacturing operation (i.e.,the hydroforming operation). Therefore, primary tube 200 may provide animproved door sealing surface as compared to the known cab frame inwhich a door sealing surface is assembled from a number of once-separatecomponent parts that are subsequently welded together.

In still further accordance with the disclosure, surface 217 of each ofthe two (2) portions 210 may include holes 219 formed during manufactureof primary tube 200, which may be configured to receive fasteners forconnection of door hinges to primary tube 200. Thus, doors can beconnected to either side of primary tube 200, regardless of whetherprimary tube 200 is on the left side or the right side of cab frame 100.Unlike the case with the known cab frame, holes for connection of doorhinges need not be formed during a separate operation, such as duringassembly of cab frame 100. Thus, manufacture of the cab built on cabframe 100 is simplified as compared to the manufacture of the cab on theknown cab frame.

Although the dimensions of primary tube 200 and secondary tubes 300 and400 may be measured relative to edges and faces of the tubes 200, 300,and 400, as set forth above, it is to be understood that the dimensions,including the widths and the depths, may be measured at least in partrelative to cab frame 100 when assembled to include two (2) primarytubes 200 and either two (2) secondary tubes 300 or two (2) secondarytubes 400. For example, the width W210 may be measured about parallel tothe plane in which uppermost portions of primary tubes 200, secondarytubes 300, and/or secondary tubes 400 are disposed, and about across afront face of portion 210. The depth D210 may be measured about parallelto the plane, and about perpendicular to the width W210. The width W230may be measured about perpendicular to the plane, and about across afront face of portion 230. The depth D230 may be measured about parallelto the plane, and about perpendicular to the width W230. The width W330may be measured about perpendicular to the plane, and about across afront face of portion 330. The depth D330 may be measured about parallelto the plane, and about perpendicular to the width W330. The width W430may be measured about perpendicular to the plane, and about across afront face of portion 430. The depth D430 may be measured about parallelto the plane, and about perpendicular to the width W430.

Other characteristics of primary tube 200 may be chosen to achieve otheradvantages. For example, shapes or contours of one or both of portions210, for one or both of primary tubes 200, may be chosen to increase ormaximize operator visibility in an area surrounding the mobile machineand/or the cab constructed on cab frame 100, when the operator is in thecab or cab frame 100.

It is to be understood that this disclosure may be used with a cab framethat does not include a ROPS, or with cab frames having different ROPSrequirements. Depending on whether the cab frame does not include a ROPSrequirement, or whether the cab frame has a less stringent ROPSrequirement, for example, tubes having different characteristics may beused to form one or both of primary tubes 200, and/or one or both ofsecondary tubes 300. By way of further example, tubes having thinnerwalls may be used when there is no ROPS requirement or a reduced ROPSrequirement for the cab frame.

It will be apparent to those skilled in the art that variousmodifications and variations may be made to the cab frame for the mobilemachine without departing from the scope of the disclosure. Otherembodiments of the disclosed cab frame will be apparent to those skilledin the art from consideration of the specification and practice of thecab frame disclosed herein. It is intended that the specification andexamples be considered as exemplary only, with a true scope of thedisclosure being indicated by the following claims and theirequivalents.

1. A frame for a cab of a mobile machine, the cab frame comprising: afirst primary tube comprising first and second about verticallyextending portions and an about horizontally extending portion, theabout vertically extending portions configured to be connected to themobile machine, and the about horizontally extending portion disposedbetween the about vertically extending portions, the first primary tubebeing formed by hydroforming; a second primary tube comprising first andsecond about vertically extending portions and an about horizontallyextending portion, the about vertically extending portions of the secondprimary tube configured to be connected to the mobile machine, and theabout horizontally extending portion of the second primary tube disposedbetween the about vertically extending portions of the second primarytube, the second primary tube being formed by hydroforming; and firstand second secondary tubes, each of the first and second secondary tubesconnecting to the first and second primary tubes.
 2. The cab frame ofclaim 1, wherein the first about vertically extending portion of thefirst primary tube has a first width and a first depth, and the abouthorizontally extending portion of the first primary tube has a secondwidth that is different that the first width and has a second depth thatis different that the first depth.
 3. The cab frame of claim 2, whereinthe first secondary tube has a first width and a first depth each at afirst portion thereof, and the first secondary tube has a second widthand a second depth each at a second portion thereof, the second widthbeing different from the first width, and the second depth beingdifferent from the first depth.
 4. The cab frame of claim 1, wherein thefirst and second secondary tubes are connected to the first and secondprimary tubes such that uppermost surfaces of the secondary tubes aredisposed in a same plane as uppermost surfaces of the about horizontallyextending portions of the first and second primary tubes.
 5. The cabframe of claim 4, wherein uppermost surfaces of ends of the abouthorizontally extending portion of the first primary tube are disposedbelow the plane.
 6. The cab frame of claim 5, wherein uppermost surfacesof ends of the first secondary tube are disposed below the plane.
 7. Thecab frame of claim 6, wherein the first secondary tube is formed byhydroforming.
 8. The cab frame of claim 1, wherein the abouthorizontally extending portion of the first primary tube has a minimumvalue of a width at an about center thereof, the width measured aboutperpendicular to a plane defined by uppermost surfaces of the abouthorizontally extending portions of the first and second primary tubes.9. The cab frame of claim 8, wherein the about horizontally extendingportion of the first primary tube has a maximum value of a depth at theabout center thereof, the depth measured about parallel to the plane.10. The cab frame of claim 9, wherein the first secondary tube has aminimum value of a width at an about center thereof and has a maximumvalue of a depth at the about center thereof, the width of the firstsecondary tube measured about perpendicular to the plane and the depthof the first secondary tube measured about parallel to the plane. 11.The cab frame of claim 10, wherein the first secondary tube is formed byhydroforming.
 12. The cab frame of claim 1, wherein (i) a surface of thefirst about vertically extending portion of the first primary tube, (ii)a surface of the second about vertically extending portion of the firstprimary tube, and (iii) a surface of the about horizontally extendingportion of the first primary tube are disposed in a same plane, theplane configured to provide a sealing surface for a door connected tothe cab frame.
 13. A frame for a cab of a mobile machine, the cab framecomprising: a first primary tube comprising first and second aboutvertically extending portions and an about horizontally extendingportion disposed therebetween, the first primary tube having differentstrengths along a length thereof and forming a left side of the cabframe, the first primary tube being formed by hydroforming; a secondprimary tube comprising first and second about vertically extendingportions and an about horizontally extending portion disposedtherebetween, the second primary tube having different strengths along alength thereof and forming a right side of the cab frame, the secondprimary tube being formed by hydroforming; and first and secondsecondary tubes, the first secondary tube connected to the primary tubesto form a front of the cab frame, and the second secondary tubeconnected to the primary tubes to form a back of the cab frame.
 14. Thecab frame of claim 13, wherein the about horizontally extending portionof the first primary tube has a minimum value of a width at an aboutcenter thereof and has a maximum value of a depth at the about centerthereof, the width measured about perpendicular to a plane defined byuppermost surfaces of the about horizontally extending portions of thefirst and second primary tubes, and the depth measured about parallel tothe plane.
 15. The cab frame of claim 14, wherein the first secondarytube has a minimum value of a width at an about center thereof and has amaximum value of a depth at the about center thereof, the width of thefirst secondary tube measured about perpendicular to the plane and thedepth of the first secondary tube measured about parallel to the plane.16. A method of manufacturing a frame for a cab of a mobile machine, themethod comprising: forming a first primary tube by a hydroformingoperation, the first primary tube configured to form a left side of thecab frame; forming a second primary tube by a hydroforming operation,the second primary tube configured to form a right side of the cabframe; forming first and second secondary tubes; and connecting each ofthe first and second secondary tubes to both of the first and secondprimary tubes.
 17. The method of claim 16, wherein forming the firstprimary tube comprises forming the first primary tube to include firstand second about vertically extending portions and an about horizontallyextending portion, the about vertically extending portions configured tobe connected to the mobile machine, and the about horizontally extendingportion disposed between the about vertically extending portions, thefirst primary tube having different strengths along a length thereof,and wherein forming the second primary tube comprises forming the secondprimary tube to include first and second about vertically extendingportions and an about horizontally extending portion, the aboutvertically extending portions of the second primary tube configured tobe connected to the mobile machine, and the about horizontally extendingportion of the second primary tube disposed between the about verticallyextending portions of the second primary tube.
 18. The method of claim17, wherein connecting comprises connecting the secondary tubes suchthat uppermost surfaces of the about horizontally extending portions ofthe first and second primary tubes and uppermost surfaces of thesecondary tubes are disposed in a same plane, and wherein the abouthorizontally extending portion of the first primary tube has a minimumvalue of a width at an about center thereof and has a maximum value of adepth at the about center thereof, the width measured aboutperpendicular to the plane and the depth measured about parallel to theplane.
 19. The method of claim 18, wherein forming the first and secondsecondary tubes comprises forming the first secondary tube to include aminimum value of a width at an about center thereof and to include amaximum value of a depth at the about center thereof, the width of thefirst secondary tube measured about perpendicular to the plane and thedepth of the first secondary tube measured about parallel to the plane20. The method of claim 19, wherein forming the first and secondsecondary tubes comprises forming the first secondary tube by ahydroforming operation, and wherein connecting comprises welding thesecondary tubes to the primary tubes.